Telephone-transmitter.



H. F. ALBRIGHT.

TELEPHONE TRANSMITTER.

APPLICATION FILED FEB.24,1906.

921,334, Patented May 11,1909.

UNITED STATES PATENT oriuion.

HENRY F. ALBRIGHT, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRICCOMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHONE-TRANSMITTER.

Specification of Letters Patent.

Patented May 11, 1909.

Application filed February 24, 1906. Serial No. 302,696.

To all whom it may concern:

Be it known that I, HENRY'F. ALBRIGHT, citizen of the United States,residing at New York, in the county of New York and State of New York,have invented a certain new and useful Improvement in Telephone--Transmitters, of which the following a full, clear, concise, and exactdescription.

My invention relates to a telephone transmitter, and consists in variousimprovements in details,'having for their object an increase in theefficiency of the transmitter and ease and accuracy in adjustment of theparts.

I will describe my invention in detail by reference to the accompanyingdrawings, in which,

Figure 1 is a front elevation of the transmitter; Fig. 2 is a rearelevation with the c asing in section; Fig. 3 is a section on line 3-3of Fig. 2; Fig. 4 is a detail view showing the connection between thefront electrode and the corresponding cord terminal; Fig. 5 is aseparated view of the frontsupporting plate and the casing of thetransmitter.

The same reference characters are used to designate the same partsWherever they are shown.

C is a cup which forms a casing for the elect-IOdu-S c and c. The innercircumferential walls of this cup are lined as usual with a strip ofpaper (1. The back electrode c is secured to the face of the metallicpiece 6, which in turn is secured in the bottom of the cup C. The frontelectrode 0 is carried on the rear face of the metallic disk e, whichhas a threaded hub portion 0" on its front face. A mica washer d ofsufficient diameter to completely cover the opening in the cup C isslipped over the hub e and is clamped against the disk e by a nut e. Theusual granular carbon is placed in the cup between the opposingelectrodes. These parts, constituting the resistance button, are thenassembled as shown in I ig. 3, the mica washer d restin u on theinturned flanges d surrounding the ower portion of the central openingin the inverted dish-shaped bridge D. The screw threaded stud e integralwith the disk e and the threaded hu b 0", passes through a hole in thecenter of the sound-receiving diaphragm E, which is threaded on saidstud.

In order that the diaphragm may be more readily threaded on the stud, Ipreferably provide the opening therein with an interiorly threadedbushing 0 securely clamped to said diaphragm by a nut e", as shown inFig. 3. A. nut c is threaded on the end of the stud c, which projectsthrough the diaphragm. .\n insulating washer E, preferably of blottingpaper or similar material, lies between the diaphragm 1C and the rim ofthe bridge I), the diaphragm being rotated until it seats against saidblotting paper. This threaded diaphragm construction rcquires that. thediaphragm be slightly warped into place so as to firmly engage theblotting paper washer on all sides. This slight bending into position,however, does not interfere with the function of the diaphragm. Ingeneral said diaphragm should be somewhat smaller in diameter than thebridge D, in order that it may not by any possible mischance projectbeyond the edge of the bridge. By constructing the insulating washer Eof blotting paper or similar pliable material more ellicicnt results areobtained than if the ordinary thick paper or. hard rubber is used. Asoft rubber ring I) incases the periphery of the diaphragm and bridgeI), and serves to insulate the same from the transmitter casing.

The above described structure constitutes the working unit which may bereadily secured in or removed from the transmitter face plate B. Theplate B, which constitutes what is the usual front piece of thetransmitter, has an annular flange 5 within the cir cumference of whichthe working unit is adapted to be placed. The working unit is thusconfined in such manner that there is no possibility of lateraldisplacr-unent, such as would put a lateral strain on the spindleconnecting the movable electrode 0' and the diaphragm E, and which mightprevent a proper operation of said parts. The usual amping springs D areprovided. Stop plates 5 may be used to prevent the possible dislodgmentof the working unit. Without these stop plates any pulling strain, dueto the cord terminals being mounted on'thc working unit as hereinafterdescribed, would come directly on said unit, and if there were nothingbut the dam )ing springs to hold it in placethe parts might be pulledout or inured, which possibility is eliminated by the use of said stopplates.

The bridge I)- 18 provided with one orsnoro ears d winch register withcut out portions lllll III) in the llangeib, thereby preventing therotation of the bridge. This is important, since these cars prevent theaccidental rotation of the bridge and thrstud c therewith, whichrotation might vary the adjustment of the diaphragm E.-

The. working unit is insulated from the front piece-B and the casing, asshown in the drawing, The front electrode c is connccted to the terminalplate which is insulatcdly mounted on the bridge l), and has a lug 1'passing through an opening in the said bridge to which a c-oinluctorleading from the nutc may be attached. electrically connected, as shown,to the bridge 1), and a cord terminal plate if is mounted on the bridge.As is apparent, the working unit may be completely insulated from thecasing, and thereby require two cords, one for each terminal plate 1, ior the transmitter may be )rovided with a single cord, the other side ofthe working unit being grounded. The ground connection may be obtainedby means of a wire. t running from the terminal t to a screw 15 on theplate B. The fact that the cord terminal plates are anchored to the unititself is a very desirable feature, since by such construction thecomplete working unit may be easily removed and replaced by another, ifdesirable. When the cords have simple horse shoe shaped clips commonlyused, said cords may be anchored to the plates t i by screws on saidplates. However, if necessary, auxiliary cord terminal posts 1 may beprovided, as shown, suitable for receiving the style of cord'tip whichpartially protrudes from the casing.

A and A are hollow shells which form the metallic casing of thetransmitter. Theseshells are held in place in any suitable manner,preferably by L-shaped or bayonet slots (1 a which engage pins 0 on theblock B. The mouthpiece M is screw threaded in an opening in said blockB.

l. claim 2- 1. In a telephone transmitter, the combination with a frontsupporting plate, of a bridge plate having a screw-threaded openingtherein and an inturned annular flange about the front face of saidopening, and an cxteriorly threaded button threaded in said opening fromthe rear of said bridge plate against said flange, said flange therebyserving to hold the parts of said button assembled.

, 2. in a telephone transmitter, a working unit comprising a resistancevarying elciiient having a movable electrode, a circular bridge platefor supporting the same, a threaded stud attached to the movableelectrode, a diaphragm threaded on said stud, a pliable insulatingwasher between the bridge and the diaphragm, and an insulating ringincasing the circumferential edges of Theback electrode- 6 is nationwith a [rent supporting plate, of a said bridge and diaphragm.

having a central.opcning therein about which said cup is secured adiaphragm havinga central opening. an interiorly-tbreaded bushing insaid lattci' opening, a stud projecting from the movable electrode andthreaded in said bushing, a front supporting plate, material insulatingsaid bridge plate and diaphragm from each other and from said supportingplate, and cord terminals carried by said bridge plate.

4. in a telephone transmitter, the combibridge plate mounted thereon,said plates liaving'cacli a cent ral pcning, a cup having its open endsecured about the central opening in said bridge plate, an electrodesecured within said cup, a movable electrode supported about the openingin the bridge plate, c0nducting material in said cup between saidelectrodes, a suitably supported diaphragm, having a central threadedopening therein, a threaded stud projecting from said movable electrodeand threaded in said opening in the diaphragm.

5. In a telephone transmitter, thecombination with a bridge plate, of acup mounted on the rear of said plate about an opening therein, anelectrode secured within said cup, a movable electrode supported in theopening of the cup, conducting material in said cup between saidelectrodes, a screw threaded stud projecting from the movable electrode,a diaphragm threaded on said stud, and a front supporting plate having acentral opening facing said diaphragm.

6.,111 a telephone transmitter, a working unit comprising a buttonprovided with a movable electrode having a threaded stud, a diaphragmthreaded on said stud, a bridge plate carrying said button and forming asupport tor-the edges of said diaphragm,

insu ating material between said bridge plate and diaphragm and alsoncasing the edges ol the same, and terminals for said electrodes carriedby said bridge plate.

7. in a telephone transmitter, the combination with a supporting plate,of an inverted dish-shaped bridge plate supported thereby, said bridgeplate having a threaded central opening therein and an int-urned flangeaboutthe front of said opening, a resistance button comprising a cup, apair of electrodes within said cup, conducting material between saidelectrodes and a flexible cover for said cup, said cup having a threadedexterior wherebyit may be threaded in the opening in the bridge plateagainst said inturncd flange to hold said button in its assembledposition, and a diaphragm supported upon said supporting plate andconnected to one of said electrodes.

8. In a telephone transmitter, a suitably roe supported button providedwith a movable electrode having a threaded stud attached thereto, asuitably supported diaphragm having a central opening, and a bushing;se-

cured in said OFGIIiIIg, said bushing being ined to recelve saldthreadedteriorly threat stud, whereby by rotating said diaphragm it maybe adjusted on said stud.

In witness whereof, I hereunto subscribe y name this sixteenth day ofFebruary A. I I 1906.

HENRY F. ALBRIGHT. Witnesses:

N. E. NEWTON, J. W. BANCKER.

